Adopting Full Dynamic Color Palette Technology to Fulfill the High-Precision Prediction on Coal Seam Distribution

Abstract

The coal reservoir in Bowen in eastern Australia is generally 2–5 m. In view of the need of coalbed methane development, methods of seismic inversion or seismic attribute combined with drilling information are usually used for prediction. However, seismic inversion is time-consuming and can be obtained by interpolation and extrapolation of drilling information, which may not reflect the real thin reservoir information; The conventional seismic attribute analysis method only adopts one parameter. The identification of geological targets lacks a fine classification interval, and the imaging cannot carry out holographic color display. So the geological targets are often too rough imaging to clear depict the thickness and connectivity of coal seam. In this paper, the distribution of coal reservoir is predicted by using the holographic high-detailed display technology of AI seismic amplitude and waveform with high precision.

The technology includes three aspects: 1) The distribution interval subdivision of amplitude and waveform is carried out based on neural network AI technology: the spatial discrete amplitude point value is built into a data body by 3d grid interpolation technology, the neural network AI technique is used to classify and subdivide the waveforms based on the amplitude value from large to small; 2) Full dynamic palette technology: including three parts such as amplitude probability distribution curve, adjustable amplitude dynamic range, adjustable holographic color bar.The holographic color bar was adjusted according to the amplitude probability distribution curve. According to the thickness range of well point, the color zoning of the amplitude classification interval was refined to reflect the subtle changes in reservoir thickness. The amplitude dynamic range is adjusted according to the drilling reservoir thickness, and the reservoir boundary is determined to achieve the geological target of high precision display.3) obtain the color seismic amplitude plan and seismic profile In the whole frequency along the layer body, slice along layers can be cut out. According to the amplitude numerical interval and the color palette information, the color seismic profile and the amplitude property plane distribution are obtained and according to the well point information, the statistical analysis is carried out to obtain the values of reservoir thickness on each color interval. The spatial distribution of coal reservoir is researched by synthesizing the fault distribution on the amplitude section.

This technology can predict the thickness and connectivity of coal seam, faults, volcanic rocks and channels. It can be used as a reference for similar areas to solve the technical schemes of coalbed methane field structure, reservoir description and well location evaluation for petroleum companies.